The prior art is well documented with examples of attachment and mixing devices utilized with a fire extinguisher. Related references DE 10 2005 031 451 and DE 20 2005 010 596 teach an additive agent holding container 23 which is arranged outside of the conventional extinguisher and is depicted mounted to a mixing mechanism associated with an extending end of the flexible hose 13. Variants of the extinguisher can also include an interiorly disposed CO2 cartridge 19 in order to maintain pressurization within the main tank.
Neumeir, U.S. Pat. No. 6,543,547, teaches a portable foam fire extinguisher with pressurized foam stabilization including a container 6 for the fire extinguisher medium, a pressurized gas bottle 7 in communication with the container, and a fire extinguisher gun connected to the container by a hose for supplying the fire extinguishing to the fire extinguisher gun. A mixing device is connected by way of a pressure hose to the pressurized gas bottle for admixing pressurized gas to the flow of the fire extinguishing medium to the fire extinguisher gun.
Both EP 1 695 743 and FR 2 670 839 teach an additive holding body or container 11 which is arranged within an extinguisher interior. Chang, US 2009/0188681, teaches a container 40 holding a dry chemical agent and which is incorporated into a cover 20 forming an integral portion of a fire extinguisher (FIG. 3) and including a check valve 47 for introducing the agent for mixing within the interior 11 of the extinguisher.